The present invention relates to the fields of tumor biology and molecular biology, and to a method of treating angiogenesis-related diseases or conditions and, more particularly, to the inhibition of neovascularization and tumor growth and metastasis in vivo.
Perlecan is a modular proteoglycan that participates in the formation and maintenance of basement membranes in various organs (1,2). It is a major heparan sulfate proteoglycan (HSPG) secreted by endothelial cells and is a potent inhibitor of smooth muscle cell proliferation, a biological function mediated by perlecan""s block of fibroblast growth factor 2 (FGF2) activity (13) and Oct-1 gene expression (14). Perlecan has been shown to play a critical role in regulating the vascular response to injury in vivo (17).
Angiogenesis is one of the most important events in tumor progression and is greatly influenced by cell-matrix interactions taking place at the surface of the endothelial cells and at the tumor-matrix boundaries (31). HSPGs act as depots for pro- and anti-angiogenic factors and, in concert with members of the FGF and vascular endothelial growth factor (VEGF) families and their receptors, modulate various aspects of angiogenesis (9). Interestingly, various angiogenesis inhibitors have been found to be proteolytically-processed forms of basement membrane collagens types IV, XV and XVIII, the latter two being chondroitin and HSPGs, respectively (32).
The invention presented herein describes a potent inhibitor of angiogenesis: the carboxyl terminus domain, domain V, of perlecan. This fragment, xe2x80x9cendorepellin,xe2x80x9d inhibits angiogenesis and is active at nanomolar concentrations. Endorepellin interferes with endothelial cells"" adhesive properties for various substrata, including, but not limited to, fibronectin and fibrillar collagen. Endorepellin, thus, represents a novel anti-angiogenic tool for the treatment of diseases or conditions associated with movement, migration and adhesion of cells, including diseases that involve angiogenesis such as, but not limited to, tumor metastasis and growth. The present invention provides endorepellin, analogs and fragments thereof, for use in inhibiting angiogenesis.
Abbreviations
xe2x80x9cHSPGxe2x80x9d means xe2x80x9cheparan sulfate proteoglycansxe2x80x9d
xe2x80x9cHUVECxe2x80x9d means xe2x80x9chuman umbilical vein endothelial cellsxe2x80x9d
xe2x80x9cCAMxe2x80x9d means xe2x80x9cchicken chorioallantoic membrane
xe2x80x9cFGFxe2x80x9d means xe2x80x9cfibroblast growth factorxe2x80x9d
xe2x80x9cVEGFxe2x80x9d means xe2x80x9cvascular endothelial cell growth factorxe2x80x9d
xe2x80x9cLGxe2x80x9d means xe2x80x9claminin-type Gxe2x80x9d
xe2x80x9cEGxe2x80x9d means xe2x80x9cepidermal growth factor-likexe2x80x9d
Definitions
xe2x80x9cpatientxe2x80x9d as used herein can be one of many different species, including but not limited to, mammalian, bovine, ovine, porcine, equine, rodent and human.
xe2x80x9canalogxe2x80x9d as used herein is a derivative or modification of the native sequence. One skilled in the art may prepare such analogs wherein the native sequence is modified by resultant single or multiple amino acid substitutions, additions or deletions. All such modifications resulting in a derivative of endorepellin are included within the scope of the invention, provided that the molecule retains angiogenesis-inhibiting activity.
xe2x80x9csubstantial sequence homologyxe2x80x9d means at least approximately 60% homology between the amino acid residue sequence in the endorepellin analog or derivative sequence and that of endorepellin sequence.
xe2x80x9canti-angiogenesis activityxe2x80x9d and xe2x80x9cangiogenesis-inhibiting activityxe2x80x9d refers to the ability of a molecule to inhibit the growth of blood vessels.
xe2x80x9cangiogenesis-mediated diseasexe2x80x9d refers to the unregulated growth of new blood vessels that causes a disease or exacerbates an existing condition.